Download SOILS Soils are Crucial for Life on Earth

Soils are Crucial for Life on Earth
• Soils support the growth of higher plants by providing a medium for plant
roots and supplying nutrient elements that are essential to the entire plant.
• Soil properties are the principal factor controlling the fate of water in the
hydrologic system. Water loss, utilization, contamination and purification
are all affected by the soil.
• Soils function as nature’s recycling system. Within the soil, waste products
and dead bodies of plants, animals, and people are assimilated into
elements made available for reuse by the next generation of life.
• Soils provide habitats for many living organisms from small mammals and
reptiles to tiny insects and microscopic cells of vast numbers and diversity.
• Soils play a major role as an engineering medium in human built
ecosystems by providing building materials as well as being the foundation
for any construction that occurs.
The Soil Profile
REGOLITH
• O = Organic layer
• A = (Top Soil) Mostly Mineral but
darkened by organic material
• E = (Sub Soil) weathered/leached
horizon with no organic material
Just below the A Horizon
• B = Underlying layers
• C = Least Weathered part of the
soil profile
• Bedrock = Parent Material
PRIMARY SUCCESION
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ALFISOLS – High-Nutrient Soils
ANDISOLS – Volcanic Soils
ARIDISOLS – Desert Soils
ENTISOLS – New Soils
GELISOLS – Permafrost Soils
HISTOSOLS – Organic Soils
INCEPTISOLS – Young Soils
MOLLISOLS – Prairie Soils
OXISOLS – Tropical Forest Soils
SPODODOLS – Conifer Forest Soils
ULTISOLS – Low-Nutrient Soils
VERTISOLS – Swelling Clay Soils
ROCKY LAND
SHIFTING SANDS
ICE/GLACIERS
STATE SOIL?
• Texas State Motto – “Friendship”
• Texas State Tree – Pecan
• Texas State Reptile – Horned Lizard
• Texas State Flower – Bluebonnet
• Texas State Bird – Mocking Bird
• Texas State Gem – Texas Blue Topaz
• Texas State Soil – ?
SOIL PROPERTIES
• SOIL COLOR – determines soil horizons, helps identify parent
minerals, helps identify organic material present, and helps to
determine what type of environment exists in the soil
(aerobic vs anaerobic)
• Use of Munsell Charts helps to identify colors.
It is based on these three criteria:
• HUE – specific color
• VALUE – lightness or darkness
• CHROMA – color intensity
SOIL PROPERTIES
• SOIL TEXTURE – helps determine pore space available, which gives
insight into the soils water percolation, infiltration and retention
capabilities.
• PERCOLATION – movement of water through the soil
• INFILTRATION – Ground surface water entering the soil. Affected by gravity
and capillary action.
Soil Texture involves particle type and size.
SOIL PARTICLE SIZE